QPSK Modulator is simulated on Matlab , FPGA is designed on Xilinx ISE and Implemented on Xilinx Virtex - 4 Development kit

1. Hardware Implementation of QPSK Modulator for Satellite Communication Presented By : Kiran Prajapati Pradeep Santdasani Internal Guide : Dhara Shah Lecturer (EC Dept.) L C Institute of Tech . External Guide : E P Balasubramanian Group Director SPSG Space Application Center (ISRO)

6. QPSK Modulator I data Q data + Cos ω c t Modulator Output Block Diagram sin ω c t I - Signal 1 bit = 180 o 0 bit = 0 o 0 bit = 90 o 00 bit = 45 o 10 bit = 315 o 01 bit =135 o 11 bit = 225 o Q - Signal 1 bit = 270 o Constellation Description of QPSK Modulator June 9, 2009

7. QPSK Modulator Equations I - Signal sin ( ω c t - 45 ) Q - Signal -cos ω c t Phasor Diagram +cos ω c t +sin ω c t -sin ω c t sin ( ω c t - 135 ) sin ( ω c t + 45 ) sin ( ω c t + 135 ) Description of QPSK Modulator June 9, 2009 I Data Q data I Mod O/P Q Mod O/P QPSK O/P QPSK O/P Phase 0 0 sin ω c t cos ω c t sin ω c t + cos ω c t = sin ( w c t + 45 ) 45˚ 0 1 sin ω c t -cos ω c t sin ω c t - cos ω c t = sin ( ω c t + 135) 135˚ 1 0 - sin ω c t cos ω c t - sin ω c t + cos ω c t = sin ( ω c t - 45 ) 315˚ 1 1 - sin ω c t -cos ω c t - sin ω c t - cos ω c t = sin ( ω c t - 135 ) 225˚

8. QPSK Modulator Time Domain Description of QPSK Modulator June 9, 2009

10. QPSK Modulator Unipolar to Bipolar Upsampling Carrier Unipolar to Bipolar Upsampling 90 o I data Q data Multiplier Multiplier Adder QPSK Modulator Block Diagram Matlab Simulation of QPSK Modulator June 9, 2009

11. QPSK Modulator Upsampling Matlab Simulation of QPSK Modulator June 9, 2009

12. QPSK Modulator I - Signal Modulation Matlab Simulation of QPSK Modulator June 9, 2009

13. QPSK Modulator Q Signal Modulation Matlab Simulation of QPSK Modulator June 9, 2009

14. QPSK Modulator QPSK Time Domain Signal Matlab Simulation of QPSK Modulator June 9, 2009

15. QPSK Modulator Baseband Spectrum Matlab Simulation of QPSK Modulator June 9, 2009

16. QPSK Modulator QPSK Spectrum Matlab Simulation of QPSK Modulator June 9, 2009

18. QPSK Modulator Unipolar to Bipolar Upsampling Carrier Unipolar to Bipolar Upsampling 90 o I data Q data Shaping Shaping Multiplier Multiplier Adder QPSK Modulator Block Diagram Matlab Simulation of QPSK Modulator June 9, 2009

19. QPSK Modulator QPSK Spectrum Matlab Simulation of QPSK Modulator June 9, 2009

20. QPSK Modulator Carrier Frequency ƒc = 25 MHz Data Frequency ƒd = 25 MHz Roll off Factor α = 0.3 Bandwidth = 16.25 MHz Matlab Simulation of QPSK Modulator QPSK Bandwidth June 9, 2009

25. QPSK Modulator I data + Look Up Table sinw c t I Carrier Q Carrier Shaping filter Unipolar to bipolar Shaping filter Unipolar to bipolar Q data QPSK Modulated Signal Look Up Table cosw c t QPSK Modulator Block Diagram Hardware Implementation of QPSK Modulator June 9, 2009

27. QPSK Modulator I & Q Carrier Signal Generation Hardware Implementation of QPSK Modulator June 9, 2009

28. QPSK Modulator Simulated Implemented QPSK Modulated Signal Hardware Implementation of QPSK Modulator June 9, 2009

29. QPSK Modulator QPSK Spectrum Hardware Implementation of QPSK Modulator June 9, 2009

30. QPSK Modulator Simulated Implemented QPSK Spectrum : Results June 9, 2009

31. QPSK Modulator Hardware Setup : Results June 9, 2009

35. Thanks